1. Field of the Invention
The invention relates to anOptical disk drive, and more particularly, to anOptical disk drive is capable of reducing mechanical noise and noise due to air currents.
2. Description of the Prior Art
An optical disk drive is presently standard equipment of a computer, like CD ROM, DVD ROM and CD RW drives, for example reading speed of CD ROM drive has quickly developed from a low rotation rate (low reading speed) of 2×, 4× to a high rotation rate (high reading speed) of 52×. As well, the rotation rate of CD ROM exceeds 10,000 rpm for satisfying users” demand of data reading speed. Because of the high rotation rate, when the CD ROM drive operates, its components, such as a spindle motor, a track seeking motor, a reading probe and a gear wheel, will generate mechanical noise. Similarly, the high rotation rate of CD ROM itself will cause internal air currents and therefore produce a high decibel noise level.
Referring to FIG. 1 and FIG. 2, a prior art CD ROM drive 1 comprises a bottom base 11, a top cover 12 coupling to the bottom base 11, and a playing mechanism 14 positioned in a containing space 13 defined between the top cover 12 and the bottom base 11. The playing mechanism 14 is capable of being drawn out for holding a disk 16 so as to read and/or write data.
A space distance between the top of playing mechanism 14 and the inner surface 121 of the top cover 12 is narrow, therefore, when an air current 100 around the disk 16 is moved out by centrifugal force, there are no sufficient air currents for supply, which produces an unstable atmospheric field. Consequently, the disk 16 is vibrated and its reading accuracy is affected, and a wind shear caused by the flow of air current 100 will also generate noise. When additionally considering the mechanical noise generated by the operation of playing mechanism 14, the total noise of CD ROM drive 1 will be more serious.
A method of reducing noise of the prior art CD ROM drive 1 is sticking one or more sound absorbing strips formed of a high polymer foaming material, such as a rubber foaming material or a polyurethane foaming material, on the inner surfaces of the top cover 12 or the bottom base 11 for filling the gap between the top cover 12 and the playing mechanism 14 or filling the gap between bottom base 11 and the playing mechanism 14 so as to avoid noise spreading out the CD ROM drive 1. However, the noise produced from the wind shear caused by the flow of the air current 100 cannot be effectively reduced.
Therefore, how to improve the mechanical noise and the noise due to air current of the CD ROM drive 1 is currently one of the most important issues.